The construction of such doors which is most commonly used in Australia involves the manufacture of a pre-assembled pocket comprising vertical jamb and rear members and horizontal rails. This pocket is installed within an opening provided in the wall to accommodate the pocket and the doorway, and a removeable door track is mounted within the pocket and extending across the doorway.
In order that the track may be installed after fixing-out is complete, and to enable its removal for cleaning or other maintenance, in these prior art arrangements the track is supported within the pocket by the engagement of bayonet slots with spigots located respectively adjacent the inner end of the track and in the region of the jamb near the centre of the track. The track is, of course, subsequently fixed to the head of the door opening.
Although this approach has enabled cavity mounted doors to be installed with considerable economy, several disadvantages have been inherent in the procedures employed. As the track has been mounted on spigots (which may be formed by screws) located in slots on a side flange, it has been necessary to specify left or right handed fixing. As the load of the door is carried in cantilever fashion from the side flange, some twisting or bending of the track will occur, this being particularly troublesome where rails of inadequate stiffness are employed.
A further disadvantage which this prior art system has in common with its more complex and expensive alternatives such as permanently installed top-suspended tracks, is the inability of the track to accommodate inaccuracies in wall construction or warping of the door or pocket, and these may result in scraping or jamming of the door at some point within the pocket.
A considerable problem encountered in the prior art arises from the difficulty of actually locating the track end slot on the inner spigot. As the fixer is literally working in the dark, there are occasions where the end spigot is not engaged in its slot, with unsatisfactory installation resulting.
The present invention provides an approach to the hanging of cavity mounted sliding doors which overcomes these disadvantages.
The invention is also directed to the provision of a cavity mounted door construction which facilitates the use of such doors more readily with thin-wall construction, and which is more readily adaptable to the variations in wall thickness which are found in practice.